Writing instrument



Oct. l, 1957 A. A. DUCHARME WRITING INSTRUMENT Filed oct. 12, 195s INVENTOR Arma@ A Jaca/WM5 ATTORNEY United States Patent Office ,A 2,808,032 Patented Oct. 1, 1957 WRITING INSTRUMENT Arthur A. Ducharme, Providence, R. I.

Application October 12, 1955, Serial No. 539,985

2 Claims. (Cl. 1Z0-42.03)

This invention relates to writing instruments and more specifically to a type of writing instrument wherein the writing tip is automatically extended from housed condition and maintained in extended writing condition when the instrument is used under normal conditions of writing pressure and writing angle.

A uniquely designed guard sleeve is slidably mounted on a marking cartridge contained within the writing instrument, this sleeve being biased forwardly to a housing condition over the writing tip of the cartridge by a sensitive biasing means. The nose of the guard sleeve has a riding peripheral edge which contacts the surface to be written on prior to extension of the writing tip and remains in riding contact with the surface after extension of the writing tip into contact with the surface for the writing operation. y

It will be appreciated therefore that the instant invention involves a writing instrument which is used in the normal manner, that is, at the normal writing angle and with the normal writing pressure. Two spaced portions of the instrument contact the surface being written on at all times during use, these being the writing tip and the riding edge which upon contact with the surface uncovers the writing tip. Adjustment means are provided for precision setting of the moving elements.

Attempts to develop a writing instrument of this nature have been made (see Davis Pat. 2,446,044) and it is believed th-at the present invention provides the design which is structurally and economically feasible and which in fact satisfies the need.

Other important objects and advantageous features of my invention will be apparent from the following description and accompanying drawings wherein for purposes f illustration herein a specific embodiment of my invention is set forth in detail and wherein:

Fig. 1 is a side view of the writing instrument of the instant invention;

Fig. 2 is an enlarged longitudinal sectional view of the writing instrument of Fig. 1 with the middle portion cut-away and with the writing tip in housed condition; and

Fig. 3 is an enlarged longitudinal sectional view of the forward writing tip end of Fig. 2 with the writing tip extended into writing condition.

Referring to Figs. l-3, it will be seen that the writing instrument of the instant invention comprises an elongated tubular body having a tube 16 and a cap 17, the cap having external threads 18 which engage the internal threads 19 at the rearward end of the tube 16. The cap 17 has a socket 20 in its forward end which receives and supports the rearward end of the marking cartridge 21, spacers 22 being provided at the base of the socket 20 to provide for precise adjustment of the parts as will be later explained.

The tube 16 has an inner wall 23 and a forward end portion terminating in a forward end wall 24, the forward end portion being inwardly swaged as at 25 to form a rearwardly facing internal annular ridge 26 which functions as an internal stop.

A guard sleeve generally identified by numeral 27 is mounted at the forward end portion of the tube 16 with its bearing means 28 slidably positioned within the tube 16 and its forwardly tapered nose 29 extending forwardly beyond the end wall 24 of the tube 16. The nose Z9 has an annular rearwardly facing shoulder 30 at its rear` ward end which is aligned for abutment with the end wall 24 of the tube 16 to limit rearward movement of the guard sleeve. v

The outer surface of the bearing means 28 has a forward annular bearing 31 and a rearward annular bearing 32 in sliding contact with the inner wall 23 of tube 16 on opposite sides of the stop or ridge 26. The reduced portion 33 between the bearings 31 and 32 has an outer diameter smaller than the inner diameter of the internal stop 26 to permit sliding movement without friction at this point. It will be noted that the rearward bearing 32 has a diameter slightly larger than the stop 26 and that the forward face and edge 34 of the rearward bearing 32 are aligned for abutment with the stop 26 to limit forward movement of the guard sleeve 27.

The marking cartridge 21 extends from the socket 20 forwardly through the tube 16, and through the enlarged rearward bearing passage 35 and the reduced forward bearing passage 36 of the guard sleeve 27. The cartridge has an annular shoulder 37 at its forward end portion and extending forwardly therefrom a writing tip which includes a tubular end portion 38 of less diameter than the bearing passage 35 and a revolvable ball 39, this ball upon movement over a surface 40 being rotated to apply the marking composition contained within the cartridge 21.

An internal annular spring seat 41 is formed by the meeting of the two bearing passages 35 and 36 of the guard sleeve 27. A coil spring 42 surrounds the tubular end portion 3S and extends from the spring seat 41 to the cartridge shoulder 37. The spring-42 is designed to bias the guard sleeve 27 forwardly into the position shown in Fig. 2.wherein the marking tip is completely housed.

The nose 29 of the guard sleeve tapers forwardly from a diameter equal to the diameter of the end wall 24 to a comparatively small diameter. The terminal forward end of the nose 29 has a riding peripheral edge 43 of an `outside diameter larger than the writing tip by a predetermined amount, this predetermined amount being such that the writing tip is automatically projected into contact with the surface 40 when the riding edge 43 is pressed against the surface with normal writing pressure and at the normal writing contact angle. The riding edge 43 remains in contact with the surface for the entire period the writing tip is in contact with the paper. When the instrument is lifted from the paper, the spring 42 automatically slides the guard sleeve 27 forward to house the writing tip. The instrument may then be placed in the users pocket without further retraction operations of the writing tip or the attachment of protective caps.

It will be appreciated that the socket 20 and the bearing passages 35 and 36 support the marking cartridge in a fixed position within the tubular body 15. Since the springs 42 will vary somewhat in length and tension, means are provided for adjusting the position of the mark* ing cartridge 21 within the tubular body 15. This adjustment means in the embodiment shown comprises the spacer discs 22 positioned in the base of the socket 2d. By proper selection of the number of spacers 22 in relation to the unstressed length of the spring 42, the precise setting of the writing tip within the guard sleeve can be attained.

As seen in Fig. 3, the guard sleeve shoulder 30 is rearwardly positioned in abutment with the tube end wall 24 during the Writing openation. Also the guard forward bearing passage 36 is positioned in complete bearing engagement with the critical tubular end portion 38 of the cartridge 21, thereby bracing the forward end of the cartridge 21 during the writing operation.

It will be understood that the normal writing angle varies somewhat with each individual.` Approved and usual usage` involves a.contact anglebetween a vertical axis and a horizontal axis, for instance between 15 land 80 to 85 degrees. It is believed the most usual writing angle is between 30 and 70 degrees. Writing pressure is light and varies with the user as well as the writing composition. The instant invention requires only the usual pressure.

It will be seen therefore that my invention comprises a marking member which is made up of the tubular body and the marking cartridge which has a forward writing tip with a ball at the end thereof. At the forward end a guard sleeve surrounds the writing tip and means are provided for slidably` mounting'the guard sleeve on the marking member, this means enabling for-wardand rearward movement of the guard sleeve relative to the writing tip. In the embodiment .shown the guard sleeve is rotatable with regard to the writing tip. The guard sleeve is urged to a forward position for housing the Writingtip by suitable biasing means, this biasing means being responsive to normal writing pressure on a surface to allow movement of the guard sleeve rearwardly with relation to the writing tip, thereby to uncover the writing tip. Suitable means are provided to limit the forward and rearward movement of the guard sleeve and adjusting means may he provided if desired for precisely positioning the marking cartridge in the tubular body. The guard sleeve has a writing edge in its forward end which at the normal writing angle contacts the surface being written on and remains in contact therewith during the entire writing opv eration. This writing edge slides along the surface but does not mark the surface. p

While I have described for illustrative purposes a preferred form of the invention, various modifications within its scope may be apparent to those skilled in the art and for that reason I wish to limit myself only within the scope of the appended claims.

I claim:

1. A writing instrument comprising an elongated tubular body having an inner wall, an annular forward end wall, an internal annular ridge forming an internal stop at the forward end portion of said inner wall, and a closed rearward end provided with a socket, a guard sleeve having a forwardly tapering nose at its forward end, said nose having a shoulder at its rearward end aligned for abutment with said forward end wall of said body to limit rearward movement of said guard sleeve, said guard sleeve having a bearing means at its rearward end slidably positioned within the forward end of said body, said bearing means including a forward annular bearing and a rearward annular bearing in sliding contact with said inner wall on opposite sides of said stop, the outer diameter of said bearing means between said forward and rearward bearings being less than the inner diameter of said internal stop, the forward end of said rearward bearing being aligned for abutment with said internal stop to limit forward movement of said guard sleeve, a marking cartridge seated in said socket of said tubular body and extending forwardly linto said nose, said cartridge having an annular shoulder at its forward end portion and a writing tip at its forward end, said guard sleeve having an internal annular spring seat, coil spring means sunounding said cartridge and extending from said spring seat rearwardly to said cartridge shoulder, said spring means biasing said guard sleeve forwardly to completely house said writing tip, said nose of said guard sleeve having a riding peripheral edge of an outside diameter larger than the diameter of the writing tip by a predetermined amount to cause automatic projection of said writing tip into contact with a surface when said riding edge is pressed against said surface at the normal writing contact angle.

2. A writing instrument in accordance with claim l and including adjustment means positioned in said tubular body for positioning said marking cartridge at a predetermined position within said tubular body.

References Cited in the tile of this patent UNITED STATES PATENTS 2,432,061 Chesler Dec. 2, 1947 2,435,185 Reynolds Ian. 27, 1948 2,446,044 Davis July 27, 1948 

